Remove main thread double hop from screenshots
The SF main thread is accessed twice during screenshots,
which leads to possible inconsistent states between jumps
onto the main thread. Removing the double hop preserves
correctness and reduces the amount of computation taking place
on the main thread. The only time the main thread should be
accessed should be when getting layer snapshots. All other
work related to screenshots can take place in a binder thread.
Bug: b/294936197, b/285553970
Test: atest SurfaceFlinger_test
Flag: com.android.graphics.surfaceflinger.flags.single_hop_screenshot
Change-Id: If9fd36f82c2d550bc0821b52fef3ea88b8099116
diff --git a/services/surfaceflinger/RegionSamplingThread.cpp b/services/surfaceflinger/RegionSamplingThread.cpp
index 59eb7f5..5add290 100644
--- a/services/surfaceflinger/RegionSamplingThread.cpp
+++ b/services/surfaceflinger/RegionSamplingThread.cpp
@@ -348,17 +348,30 @@
constexpr bool kGrayscale = false;
constexpr bool kIsProtected = false;
- if (const auto fenceResult =
- mFlinger.captureScreenshot(SurfaceFlinger::RenderAreaBuilderVariant(
- std::in_place_type<DisplayRenderAreaBuilder>,
- sampledBounds, sampledBounds.getSize(),
- ui::Dataspace::V0_SRGB,
- kHintForSeamlessTransition,
- true /* captureSecureLayers */, displayWeak),
- getLayerSnapshotsFn, buffer, kRegionSampling, kGrayscale,
- kIsProtected, nullptr)
+ SurfaceFlinger::RenderAreaBuilderVariant
+ renderAreaBuilder(std::in_place_type<DisplayRenderAreaBuilder>, sampledBounds,
+ sampledBounds.getSize(), ui::Dataspace::V0_SRGB,
+ kHintForSeamlessTransition, true /* captureSecureLayers */,
+ displayWeak);
+
+ FenceResult fenceResult;
+ if (FlagManager::getInstance().single_hop_screenshot() &&
+ FlagManager::getInstance().ce_fence_promise()) {
+ std::vector<sp<LayerFE>> layerFEs;
+ auto displayState =
+ mFlinger.getDisplayAndLayerSnapshotsFromMainThread(renderAreaBuilder,
+ getLayerSnapshotsFn, layerFEs);
+ fenceResult =
+ mFlinger.captureScreenshot(renderAreaBuilder, buffer, kRegionSampling, kGrayscale,
+ kIsProtected, nullptr, displayState, layerFEs)
.get();
- fenceResult.ok()) {
+ } else {
+ fenceResult =
+ mFlinger.captureScreenshotLegacy(renderAreaBuilder, getLayerSnapshotsFn, buffer,
+ kRegionSampling, kGrayscale, kIsProtected, nullptr)
+ .get();
+ }
+ if (fenceResult.ok()) {
fenceResult.value()->waitForever(LOG_TAG);
}